Mary is Our Queen, And Her Dominion is Vast.
Pope Pius XII explained the theological reasons for giving Mary the title of Queen. On May 13, 1946, he made a broadcast over the Vatican Radio to Fatima, in which he highlighted Mary’s Queenship in relation to her role in the economy of salvation. He said:
He, the Son of God, reflects on His heavenly Mother the glory, the majesty and the dominion of His kingship, for, having been associated to the King of Martyrs in the unspeakable work of human Redemption as Mother and cooperator, she remains forever associated to Him, with a practically unlimited power, in the distribution of the graces which flow from the Redemption. Jesus is King throughout all eternity by nature and by right of conquest: through Him, with Him, and subordinate to Him, Mary is Queen by grace, by divine relationship, by right of conquest, and by singular choice [of the Father]. And her kingdom is as vast as that of her Son and God, since nothing is excluded from her dominion.
How to Enthrone Mary Immaculate Queen in Your Home